lastwhispers
diff --git a/‎java-advance/groovy/src/main/java/cn/cunchang/PaymentRequestOrderBO.java‎
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diff --git a/‎java-basic/basic/pom.xml‎
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diff --git a/‎java-basic/basic/src/main/java/cn/cunchang/Main.java‎
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diff --git a/‎java-basic/basic/src/main/java/cn/cunchang/collection/Intersection.java‎
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diff --git a/‎java-basic/basic/src/main/java/cn/cunchang/decimal/BigDecimalTest.java‎
Lines changed: 9 additions & 2 deletions b/‎java-basic/basic/src/main/java/cn/cunchang/decimal/BigDecimalTest.java‎
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diff --git a/‎java-basic/basic/src/main/java/cn/cunchang/fastjson/JSONObjectTest.java‎
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diff --git a/‎java-basic/basic/src/main/java/cn/cunchang/guava/bloomfilter/TestBloomFilter.java‎
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diff --git a/‎java-basic/basic/src/main/java/cn/cunchang/guava/cache/TestCache.java‎
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@@ -2,10 +2,6 @@
 
 import lombok.Data;
 
-/**
- * @Author: chenan
- * @Date: 2021/1/29 18:38
- */
 @Data
 public class PaymentRequestOrderBO {
 
 
@@ -43,17 +43,59 @@
             <version>2.11.1</version>
         </dependency>
 
+        <!--    fastjson    -->
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>fastjson</artifactId>
             <version>1.2.80</version>
         </dependency>
 
+        <!--    lombok    -->
         <dependency>
             <groupId>org.projectlombok</groupId>
             <artifactId>lombok</artifactId>
             <version>1.18.22</version>
         </dependency>
+
+        <!--    guava    -->
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>30.1.1-jre</version>
+        </dependency>
+
+        <!--    guava    -->
+        <dependency>
+            <groupId>cn.hutool</groupId>
+            <artifactId>hutool-all</artifactId>
+            <version>5.8.0</version>
+        </dependency>
+
+        <!--    pinyin4j    -->
+        <dependency>
+            <groupId>com.belerweb</groupId>
+            <artifactId>pinyin4j</artifactId>
+            <version>2.5.0</version>
+        </dependency>
+
+
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-expression</artifactId>
+            <version>5.2.7.RELEASE</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>3.11</version>
+        </dependency>
+
+        <dependency>
+            <groupId>commons-collections</groupId>
+            <artifactId>commons-collections</artifactId>
+            <version>3.2.2</version>
+        </dependency>
     </dependencies>
 
     <build>
 
@@ -0,0 +1,60 @@
+package cn.cunchang;
+
+import com.alibaba.fastjson.JSON;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * @author kaisui
+ * @description
+ * @date 2022/12/26
+ */
+public class Main {
+    static Map<Integer, Integer> map = new HashMap<>();
+
+    /**
+     * 判断数组中的数是否可以组成另一个数
+     * a*n+b*m=c
+     */
+    public static void main(String[] args) {
+        // a*n+b*m=c
+        //1、n=1、m=1 || n=0||m==0
+        Integer[] arr = {50, 10};
+        int c = 60;
+        //2、n>1，m=1 || n=1，m>1
+//        Integer[] arr = {50, 10};
+//        int c = 110;
+        //
+        //3、n>1，m>1
+//        Integer[] arr = {50, 90};
+//        Integer[] arr = {50, 80};
+//        int c = 260;
+        boolean xxxx = xxxx(arr, c);
+        if (xxxx) {
+            System.out.println("找到了：" + JSON.toJSONString(map));
+        } else {
+            System.out.println("没找到");
+        }
+    }
+
+    private static boolean xxxx(Integer[] arr, int c) {
+        if (c == 0) {
+            return true;
+        }
+        if (c < 0) {
+            return false;
+        }
+        for (int i = 0; i < arr.length; i++) {
+            map.put(arr[i], map.getOrDefault(arr[i], 0) + 1);
+            c = c - arr[i];
+            if (xxxx(arr, c)) {
+                return true;
+            }
+            // 回溯
+            c = c + arr[i];
+            map.put(arr[i], map.get(arr[i]) - 1);
+        }
+        return false;
+    }
+}
@@ -18,41 +18,41 @@ public void test1(){
     }
 
     public static void main(String[] args) {
-        Set<Integer> result = new HashSet<Integer>();
-        Set<Integer> set1 = new HashSet<Integer>() {
+
+        HashSet<Integer> set1 = new HashSet<Integer>() {
             private static final long serialVersionUID = 1L;
             {
                 add(1);
-                add(3);
-                add(5);
+                add(2);
             }};
 
-        Set<Integer> set2 = new HashSet<Integer>(){
+        HashSet<Integer> set2 = new HashSet<Integer>(){
             private static final long serialVersionUID = 1L;
             {
-                add(1);
                 add(2);
                 add(3);
             }};
         System.out.println("set1:"+set1);
         System.out.println("set2:"+set2);
-        //交集
 
+        HashSet<Integer> result = new HashSet<Integer>();
+
+        //交集
         result.addAll(set1);
         result.retainAll(set2);
-        System.out.println("交集:"+result);
+        System.out.println("交集:"+result);//交集:[2]
 
         //差集
         result.clear();
         result.addAll(set1);
         result.removeAll(set2);
-        System.out.println("差集:"+result);
+        System.out.println("set1-set2,差集:"+result);//差集:[1]
 
         //并集
         result.clear();
         result.addAll(set1);
         result.addAll(set2);
-        System.out.println("并集:"+result);
+        System.out.println("并集:"+result);//并集:[1, 2, 3]
 
     }
 
 
@@ -38,7 +38,6 @@ public class BigDecimalTest {
     }
 
     /**
-     *
      * BigDecimal.setScale()方法用于格式化小数点
      * setScale(1)表示保留一位小数，默认用四舍五入方式
      * setScale(1,BigDecimal.ROUND_DOWN)直接删除多余的小数位，如2.35会变成2.3
@@ -48,7 +47,6 @@ public class BigDecimalTest {
      * setScaler(1,BigDecimal.ROUND_CEILING)接近正无穷大的舍入
      * setScaler(1,BigDecimal.ROUND_FLOOR)接近负无穷大的舍入，数字>0和ROUND_UP作用一样，数字<0和ROUND_DOWN作用一样
      * setScaler(1,BigDecimal.ROUND_HALF_EVEN)向最接近的数字舍入，如果与两个相邻数字的距离相等，则向相邻的偶数舍入。
-     *
      */
     @Test
     public void test格式化小数点() {
@@ -72,5 +70,14 @@ public class BigDecimalTest {
         System.out.println(new BigDecimal("1").compareTo(new BigDecimal("0")) <= 0);
     }
 
+    @Test
+    public void test3() {
+        BigDecimal taxAmount = new BigDecimal("0.001");
+        BigDecimal originTaxAmount = new BigDecimal("0.001");
+        BigDecimal exchangeRate = new BigDecimal("1");
+        BigDecimal calOriginTaxAmount = taxAmount.divide(exchangeRate,
+                5, BigDecimal.ROUND_HALF_UP);
+        System.out.println(calOriginTaxAmount.compareTo(originTaxAmount) != 0);
+    }
 
 }
@@ -0,0 +1,23 @@
+package cn.cunchang.guava.bloomfilter;
+
+import com.google.common.hash.BloomFilter;
+import com.google.common.hash.Funnel;
+import com.google.common.hash.Funnels;
+
+public class TestBloomFilter {
+
+    public static void main(String[] args) {
+        Funnel<Integer> funnel = Funnels.integerFunnel();
+        int size = 1000_000;
+        double errorChance = 0.001;        //错误率
+        BloomFilter<Integer> filter = BloomFilter.create(funnel, size, errorChance);
+        for (int i = 0; i < size; i++) {
+            filter.put(i);
+        }
+        for (int i = 0; i < size; i++) {
+            if (!filter.mightContain(i)) {
+                System.out.println("发现不存在的数据 : " + i);
+            }
+        }
+    }
+}
@@ -0,0 +1,40 @@
+package cn.cunchang.guava.cache;
+
+import com.google.common.cache.*;
+import org.junit.Test;
+
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Guava的Cache
+ * @author lastwhisper
+ * @date 2020/6/2
+ */
+public class TestCache {
+
+    // https://github.com/zhuzhenke/common-caches
+    @Test
+    public void testCacheUse() throws Exception{
+
+        LoadingCache<String, String> loadingCache = CacheBuilder.newBuilder()
+                .expireAfterAccess(10, TimeUnit.SECONDS)
+                .maximumSize(1000)
+                .removalListener(new RemovalListener<Object, Object>() {
+                    @Override
+                    public void onRemoval(RemovalNotification<Object, Object> notification) {
+
+                    }
+                })
+                .build(new CacheLoader<String, String>() {
+                    @Override
+                    public String load(String key) throws Exception {
+                        return key;
+                    }
+                });
+
+        System.out.println(loadingCache.get("key"));
+
+
+    }
+
+}